用王斌会老师书中的mvstats包做距离判别，但是出现如下问题：
错误于solve.default(cov, ...) :
  系统计算上是奇异的: 倒条件数=6.55877e-20
代码如下：
#输入待测样本
class1<-data.frame(
x1=c(6,-11,90.2,-4,0,0.5,-10,0,20,-100,-100,13,-5,10,-8,0.6,-40.0),
x2=c(-11.5,-18.5,-17,-15,-14,-11.5,-19,-23,-22,-21.4,-21.5,-17.2,-18.5,-18,-14,-13,-20),
x3=c(19,25,17,13,20,19,21,5,8,7,15,18,15,14,16,26,22),
x4=c(90,-36,3,54,35,37,-42,-35,-20,-15,-40,2,18,50,56,21,-50)
)
#待测样本分类
temp<-c(1,3,2,1,2,3,3,1,3,1,2,2,1,1,1,3,3)
t<-factor(temp)
attach(class1)
library(mvstats)
#判定待测样本
discrim.dist(cbind(x1,x2,x3,x4),t)